The NEC in the United States has no limit on the number of outlets per circuit for residential use. Some jurisdictions have or have had a commercial restriction of 180va per yoke or strap. Because the query specifies 14 gauge wire, we utilize 80 percent of the maximum draw, or 12 amps. Therefore, you can put up to 24 outlets on this circuit.
In Europe, where they use 20-amp circuits, people sometimes try to be clever and run two 14-gauge wires into one outlet box, but that's illegal there too. The only way to do that is if the outlet boxes are separated by a panel or breaker within the house, which means these two wires are part of separate circuits. Otherwise, each outlet takes a single 14-gauge wire.
In Canada, where they use 15-amp circuits, people also try to be clever by splitting one 14-gauge wire into two 10-gauge wires inside the wall plate. This works fine until someone adds a third receptacle, when all of a sudden you're using more than 15 amps through any one conductor! That's why they tell you to always use at least three different conductors when wiring multiple outlets.
By the way, if you're wondering what voltage 14-gauge wire is, it's actually just plain old 2-voltage wire with a thick insulation jacket over it.
You may connect 12 outlets protected by a 15-amp breaker using 14-2 wire. The other 2 circuits can be used with 11-2 or 11-3 cable (each providing one strand of copper conductors per circuit). This arrangement is called "doubling up" on wire because you are using all four strands of wire in each conductor. Double-stuff wiring methods like this are required by law for circuits that carry electrical power.
Wiring diagrams show which colors go where on houses and buildings. Knowing these colors is important if you need to make changes or add wires later. For example, if you want to add a second telephone line to an existing house wiring system, you will need to either replace the old phone line with new copper piping or use fiber-optic cable instead. Either option requires knowing which color goes where on the wiring diagram. If you're not sure who supplies your electricity, contact your local utility company. They'll be able to help you determine what color wire goes where on your property.
The United States government requires certain types of buildings to be wired for emergency use only (E/U). These buildings include hospitals, schools, churches, libraries, and museums.
For general use receptacles in commercial buildings, it is limited to 180VA per duplex or single receptacle. Therefore, on a 12/2 Romex cable not otherwise subject to ampacity derating and protected by a 20 amp circuit breaker, that would allow a maximum of 13 receptacles. If the building has more than one floor, then each floor can have up to 10 receptacles.
The main limitation to this size cable is that it cannot be used as the sole means of distribution in a commercial setting where there are light fixtures involved because it is not large enough to carry the current needed. If all the rooms on a floor are using lights they will need to be switched off and on again to reset the recharger circuits on the receptacles. This is called "recharging" the circuit. The only way to do this safely is with a power switch or circuit breaker.
In other words, 12-2 wiring can only be used in a non-commercial setting where the additional cost is not justified by the increased reliability provided by larger cables. In any case, if you run out of conduit early, 6-3 or 9-0 wiring can always be used instead.
12-2 wiring can be used in a residential setting as long as each house can handle at least 15 amps. If the houses are separate units such as apartments within a building, then they can each have up to six receptacles without overloading the circuit.